Kimio Kawaguchi

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Parallel Robust Algorithms for Constructing Strongly Convex Hulls* Wei Chen~ Koichi Wadat Kimio Kawaguchit Given a set S of n points in the plane, an e-strongly convex 6-hull of S is defined as a convex polygon P with the vertices taken from S such that no point of S lies farther than d outside P and such that even if the vertices of .F’ arc perturbed by as(More)
Wada, K. and K. Kawaguchi, Efficient fault-tolerant fixed routings on (k+ 1)connected digraphs, Discrete Applied Mathematics 37/38 (1992) 539-552. Consider a directed communication network G in which a limited number of directed link and/or node faults F might occur. A routing Q for the network (a fixed path for each ordered pair of nodes) must be chosen(More)
We consider the following partition problem: Given a set S of n elements that is organized as k sorted subsets of size n/k each and given a parameter h with 1/k ≤ h ≤ n/k , partition S into g = O(n/(hk)) subsets D 1 , D 2 , . . . , D g of size Θ(hk) each, such that, for any two indices i and j with 1 ≤ i < j ≤ g , no element in D i is bigger than any(More)
Given a set S of n points in the plane, an -strongly convex -hull of S is de0ned as a convex polygon P with the vertices taken from S such that no point of S lies farther than outside P and such that even if the vertices of P are perturbed by as much as , P remains convex. This paper presents the 0rst parallel robust method for this generalized convex hull(More)
Wada, K., Y. Luo and K. Kawaguchi, Optimal fault-tolerant routings for connected graphs, Information Processing Letters 41 (1992) 169-174. The surviving route graph R(G, pi/F for a graph G, a routing p and a set of faults F is a directed graph consisting of nonfaulty nodes with a directed edge from a node x to a node y iff there are no faults on the route(More)
A communication network G is considered in which a limited number of link and/or node faults F might occur. A routing rho for the network (a fixed path between each pair of nodes) must be chosen without knowing which components might become faulty. The diameter of the surviving route graph R(G, rho )/F (denoted by (D(R(G, rho )/F))), where two nonfaulty(More)